Gallium Cluster-Promoted In 2 O 3 Catalyst for CO 2 Hydrogenation to Methanol

In this work, highly dispersed gallium clusters are constructed on In 2 O 3 (denoted as Ga/In 2 O 3 ) to promote hydrogenation of CO 2 to methanol. Compared to pristine In 2 O 3, the Ga/In 2 O 3 catalysts show markedly improved CO 2 conversion and methanol space-time yield (STY), as well as enhanced stability over 60 h on stream. A strong electronic interaction between the loaded gallium and In 2 O 3 support, as confirmed by multiple techniques, results in well-dispersed, stable gallium clusters on In 2 O 3, which is beneficial to long-term performance. The interface between gallium clusters and the defective In 2 O 3 support serves as active sites to facilitate the activation of H 2 and CO 2 . This interfacial synergy not only enhances the adsorption and dissociation of H 2 but also effectively inhibits the strong adsorption of CO 2 as carbonate. The activated CO 2 at the interface sites can be dissociated readily into adsorbed CO for further hydrogenation into methanol.